<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body><form action="s1" method="post">
    账号:<input type="text" name="username"><br>
    密码:<input type="password" name="password"><br>
    <input type="submit" value="登录"><br>
</form>

</body>
</html>